To write an e-mail (or anything else, for that matter) you need vocabulary. Without words, you can't produce language. That is why you will study words and sentences in the next few weeks.
Make sure you know them English to Dutch as well as Dutch to English: you need to know how to write the words in English for your final e-mail.
Vocabulary Writing a formal e-mail 1
Vocabulary Writing a formal e-mail 2
Vocabulary Writing a formal e-mail 3
Vocabulary Writing a formal e-mail 4